I don't understand the author's confusion as to how a ship wreck could quietly be lifted without a trace, we were doing it in the Cold War. Granted back in 1974

I don't understand the author's confusion as to how a ship wreck could quietly be lifted without a trace, we were doing it in the Cold War. Granted back in 1974 [0] such a project was very expensive but GPS and ship stability has gotten cheaper/better and these war ships are not nearly as deep. The oil and gas industry uses GPS stabilized vessels during exploration and production. This shouldn't be that hard for a determined scavenger. 0: https://en.m.wikipedia.org/wiki/Project_Azorian https://en.m.wikipedia.org/wiki/Project_Azorian